Dominant dimensionless groups controlling heat transfer coefficient during flow condensation inside pipes

Dorao, Carlos Alberto; Fernandino, María

doi:10.1016/j.ijheatmasstransfer.2017.04.104

Cited by 30 publications

(19 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…By establishing a maximum velocity test on the film surface in an inclined tube with the same maximum speed condition for a vertical surface, identical solutions are obtained with the proviso that the first is affected by , caused by the curvature of the surface and the inclination of the tubes. The mass flows of condensate per unit width of the film on vertical and inclined surfaces are also identical, [1], [11] and it are remembered that they must be affected by, therefore it is satisfied that: Considering that the length of the tube is much larger than its diameter, and that the process is assumed to be stationary, then the temperature distribution can be treated in a simplified way as one-dimensional, therefore, according to what is stated in [18][19][20], the differential equation of temperature distribution is reduced to.…”

Section: Deduction Of An Equation For Heat Transfer Coefficient Determentioning

confidence: 95%

See 1 more Smart Citation

Mathematical modeling of two-phase media heat transfer coefficient in air cooled condenser systems

Medina¹,

Khandy²,

Carlson³

et al. 2018

IJHT

View full text Add to dashboard Cite

This paper presents the results of the continuity of the research process carried out at the Center for Energy Studies, belonging to the Faculty of Technical Sciences of the University of Matanzas, related to the production of dimensionless models for the determination of the mean coefficient of heat transfer by condensation in Air Cooled Condenser systems (ACC), inside straight and inclined tubes. The research consists in analytically obtaining the solution of the differential equation of the velocity profile, considering that the condensation is of the film type, finally the Roshenow empirical condition is combined with the theoretical solution, to generate a numerical expression that allows obtaining with A 15, 2 % deviation in 692 tests, a mean value of the heat transfer coefficient by condensation very similar to that obtained with the use of the most referenced model in the literature known and consulted, Chato's empirical model.

show abstract

Section: Deduction Of An Equation For Heat Transfer Coefficient Determentioning

confidence: 95%

“…In a number of heat transfer processes involving saturated steam, a phase change to the liquid state is experienced by the condensation mechanism. This phenomenon occurs when the steam encounters a surface at a lower temperature, [1][2][3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Mathematical modeling of two-phase media heat transfer coefficient in air cooled condenser systems

Medina¹,

Khandy²,

Carlson³

et al. 2018

IJHT

View full text Add to dashboard Cite

show abstract

“…They allow transformation of the system of mass, momentum, energy and species balance equations into non-dimensional forms, thus facilitating generalization of the theoretical and experimental results [7]. Most of the researches aimed to determine empirical heat transfer coefficients are based on this concept [8][9][10][11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Monoethanolamine Heat Exchangers Modeling Using the Buckingham Pi Theorem

Escalona¹,

Góngora-Leyva²,

Camaraza-Medina³

2019

MMEP

View full text Add to dashboard Cite

Dimensional analysis was used on this study with the aim of stablishing a model for prediction of the monoethanolamine heat exchangers output. The passive experimentation method was applied to gather 14 400 data points, since the exchangers are installed in an online amine treating unit. After identification of those parameters having a relevant effect on heat transfer processes, the Buckingham Pi theorem and the method of repeating variables were implemented. Once the dimensionless groups were formulated, the explicit equation was found by means of a least-squares regression analysis. The simulation model was evaluated by comparing predicted results against measured rich amine exit temperatures. In this respect, 98.96 % correlation, 0.023 % mean absolute percentage error and 1.376 K maximum absolute error were achieved. Findings of this research may serve as a shortcut for quick and accurate anticipation of the equipment performance, since the plant is often operated outside design parameters. Despite the above, obtained explicit equation is only valid for the studied set of heat exchangers.

show abstract

“…It is well known that in a power cycle the heat exchange is a decisive process in its efficiency, since approximately 90% of the heat extracted from the cycle is done through the condensation system. The waste heat from the steam turbine is released to the atmosphere from the cooling system, which, depending on the environmental conditions, makes this exchange from water circulation systems or direct cooling with the environment [1][2][3].…”

Section: Introductionmentioning

confidence: 99%

Simplified analysis of heat transfer through a finned tube bundle in air cooled condenser-second assessment

Camaraza-Medina¹,

Rubio-Gonzale²,

Cruz-Fonticiella³

et al. 2018

MMEP

View full text Add to dashboard Cite

This paper present a review of mathematical procedures for heat transfer studies in cross flow through finned tube pack. Is given a new model for heat transfer calculations during airflow through finned tubes bank in air cooled condenser systems (ACC). The model was correlated with a total of 783 sets of available experimental data provided by ten authors of recognized prestige in the research area. The air flow bathes a package of finned tubes with an inclination of 45 0 to 60 0 with respect to the horizontal line. The studies were performed for ST/SL intervals between 0.4 and 2, air flow velocity of 0.1 to 100 m/s, an ambient temperature of 15 to 43°C, the incident wind velocity over the installation between 0 and 45 km/h, the outer equivalent diameter of the bare tubes between 0.019 and 0.05 m, a fins height between 2.7 and 7.9 mm.The fins thicknesses ranging between 1.3 and 3.5 mm and a number of fins per unit tube length between 315 and 394. The mean deviation found was 6.9% in 85.3% of the correlated experimental data.

show abstract

Dominant dimensionless groups controlling heat transfer coefficient during flow condensation inside pipes

Cited by 30 publications

References 52 publications

Mathematical modeling of two-phase media heat transfer coefficient in air cooled condenser systems

Mathematical modeling of two-phase media heat transfer coefficient in air cooled condenser systems

Monoethanolamine Heat Exchangers Modeling Using the Buckingham Pi Theorem

Simplified analysis of heat transfer through a finned tube bundle in air cooled condenser-second assessment

Contact Info

Product

Resources

About